LS water pump and LS timing belt

GSR/B16/ITR water pumps are all the same
GSR/ITR belts are the same
B16 belt is shorter because of the deck height

DO NOT RUN LS WATER PUMP AND GSR/ITR BELT. The LS pump has a different number of teeth.

If you have "belt slap" adjust the tensioner, if that doesnt help, you may have stretched the belt, replace it. Replace the tensioner as well.